Alert archive / Colorado / Snow Squall Warnings in 2021
Snow Squall Warning 3, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this snow squall warning at Dec 15, 2021, 6:49 AM MST for 4 counties in Colorado. It was in force for 56 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Dec 15, 2021, 6:49 AM MST (13:49 UTC)
- Expired
- Dec 15, 2021, 7:45 AM MST
- In force
- 56 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Storm-based polygon
Counties Clear Creek County, CO, Gilpin County, CO, Grand County, CO, Summit County, CO
The radar
The Denver radar (KFTG), 104 km from the middle of the area, began a volume at 13:52 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Denver, CO (KDNR), launched 12:00Z, 1.8 hours before the alert went out and 217 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2403 m above ground
- 0-6 km bulk shear
- 85 kt
- 0-1 km storm-relative helicity
- 194 m²/s²
- 0-3 km storm-relative helicity
- 264 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
537
WWUS55 KBOU 151349
SQWBOU
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Snow Squall Warning
National Weather Service Denver CO
649 AM MST Wed Dec 15 2021
COC019-047-049-117-151445-
/O.NEW.KBOU.SQ.W.0003.211215T1349Z-211215T1445Z/
Summit CO-Gilpin CO-Grand CO-Clear Creek CO-
649 AM MST Wed Dec 15 2021
The National Weather Service in Denver Colorado has issued a
* Snow Squall Warning for...
East central Summit County in central Colorado...
Gilpin County in central Colorado...
Southeastern Grand County in north central Colorado...
Clear Creek County in central Colorado...
* Until 745 AM MST.
* At 648 AM MST, a dangerous snow squall was located over Dillon, or
50 miles west of Denver, moving east at 25 mph.
HAZARD...Whiteout conditions. Zero visibility in snow and blowing
snow. Wind gusts greater than 40 mph.
SOURCE...Radar and webcams.
IMPACT...Dangerous life-threatening travel.
* This includes Interstate 70 between mile markers 210 and 246.
Locations impacted include...
Idaho Springs, Georgetown, Central City, Empire, Silver Plume, Black
Hawk, Berthoud Pass, Blue Valley, Loveland Pass, Berthoud Falls, St
Marys Glacier, Aspen Springs, Bakerville, Dumont, Keystone, Echo
Lake, Guanella Pass, Brookvale and Floyd Hill.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Consider avoiding or delaying travel until the snow squall passes
your location. If you must travel, use extra caution and allow extra
time. Rapid changes in visibility and slick road conditions may lead
to accidents.
&&
LAT...LON 3956 10596 3978 10604 3991 10541 3962 10540
TIME...MOT...LOC 1348Z 266DEG 23KT 3968 10586
$$
SCHLATTERThe office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 15, 6:03 AM MST | Snow Squall Warning | BOU | Summit | 57 min |
| Dec 15, 7:47 AM MST | Special Weather Statement | BOU | Boulder, Broomfield, Denver, Jefferson | 43 min |
| Dec 15, 8:12 AM MST | Special Weather Statement | BOU | Douglas | 48 min |
Nearby
Snow Squall Warnings in Colorado, 2021Every snow squall warning in 2021
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.